[PATCH 00/26] UBIFS File Encryption

From: Richard Weinberger
Date: Fri Oct 21 2016 - 08:49:23 EST

This patch series implements file level encryption for UBIFS.
It makes use of the generic fscrypto framework as used by ext4 and f2fs.
Among file contents also file names are encrypted,
for more details on fscrypto please see [0] and [1].

To support encrypted files in UBIFS multiple preparations were needed.
Patches 1/26 and 2/26 touch fscrypto code and add support to work on
buffers instead of pages.
UBIFS has a different IO model than ext4 and f2fs because it uses MTD
instead of the block layer. But the changes are small and non-invasive.
In UBIFS itself the biggest change was supporting hash lookups.
Now UBIFS is able to provide a 64bit cookie which can be used later
to locate a file. This change will also allow us implementing proper
NFS and telldir() support, but that will be a different patch series.
Because of these changes the UBIFS write version is now 5.

As userspace component I'm currently using e4crypt from e2fsprogs with
EXT2FS_KEY_DESC_PREFIX set to "fscrypt:" instead of "ext4:".
A common tool will hopefully emerge soon[2]. I don't want an UBIFS
specific tool in mtd-utils.

The series is based in 4.8-rc7, but will be rebased soon to 4.9-rcX.
I'm still sending the series now to get feedback as soon as possible.
It can be obtained from:
git://git.infradead.org/users/rw/linux.git ubifs_crypt_v0

[0] https://lwn.net/Articles/639427/
[1] https://docs.google.com/document/d/1ft26lUQyuSpiu6VleP70_npaWdRfXFoNnB8JYnykNTg/edit
[2] http://www.spinics.net/lists/linux-fsdevel/msg103107.html

Richard Weinberger (26):
fscrypto: Add buffer operations
fscrypto: Constify struct inode pointer
ubifs: Export ubifs_check_dir_empty()
ubifs: Export xattr get and set functions
ubifs: Define UBIFS crypto context xattr
ubifs: Add skeleton for fscrypto
ubifs: Massage ubifs_listxattr() for encryption context
ubifs: Implement directory open operation
ubifs: Implement file open operation
ubifs: Enforce crypto policy in ->link and ->rename
ubifs: Preload crypto context in ->lookup()
ubifs: Massage assert in ubifs_xattr_set() wrt. fscrypto
ubifs: Enforce crypto policy in mmap
ubifs: Introduce new data node field, compr_size
ubifs: Implement encrypt/decrypt for all IO
ubifs: Relax checks in ubifs_validate_entry()
ubifs: Make r5 hash binary string aware
ubifs: Constify struct inode pointer in ubifs_crypt_is_encrypted()
ubifs: Implement encrypted filenames
ubifs: Add support for encrypted symlinks
ubifs: Rename tnc_read_node_nm
ubifs: Add full hash lookup support
ubifs: Use a random number for cookies
ubifs: Implement UBIFS_FLG_DOUBLE_HASH
ubifs: Raise write version to 5

fs/crypto/crypto.c | 65 +++++--
fs/ubifs/Kconfig | 11 ++
fs/ubifs/Makefile | 1 +
fs/ubifs/crypto.c | 45 +++++
fs/ubifs/debug.c | 14 +-
fs/ubifs/dir.c | 431 +++++++++++++++++++++++++++++++++++++++--------
fs/ubifs/file.c | 130 +++++++++++++-
fs/ubifs/ioctl.c | 40 +++++
fs/ubifs/journal.c | 202 ++++++++++++++--------
fs/ubifs/key.h | 21 +--
fs/ubifs/replay.c | 10 +-
fs/ubifs/sb.c | 59 +++++++
fs/ubifs/super.c | 17 +-
fs/ubifs/tnc.c | 168 ++++++++++++++----
fs/ubifs/ubifs-media.h | 29 +++-
fs/ubifs/ubifs.h | 82 ++++++++-
fs/ubifs/xattr.c | 112 +++++++-----
include/linux/fscrypto.h | 30 +++-
18 files changed, 1202 insertions(+), 265 deletions(-)
create mode 100644 fs/ubifs/crypto.c